The combined effect of steroids, opium drugs abuses and poverty. A very complete article on diagnosing steroids abuse that shows Sayoc the stripper, author of the bombs packages in USA, was on steroids, it can be seen on its curiously feminine face. Steroids users would not accept their feminine side, so they would go on torturing their bodies with steroids in order to turn them more "male".
https://s3.amazonaws.com/academia.edu.documents/31438708/Keane_-_Diagnosing_the_Male_Steroid_User.pdf?AWSAccessKeyId=AKIAIWOWYYGZ2Y53UL3A&Expires=1540644920&Signature=EH5aPZWw300Zk7rMRqStKDK%2BU%2FE%3D&response-content-disposition=inline%3B%20filename%3DDiagnosing_the_Male_Steroid_User.pdf
and remember this is the kind of client that sells its blood serum.